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Binary Linear Write Equalization

IP.com Disclosure Number: IPCOM000047275D
Original Publication Date: 1983-Oct-01
Included in the Prior Art Database: 2005-Feb-07

Publishing Venue

IBM

Related People

Authors:
Davie, NR Schneider, RC [+details]

Abstract

A general method of write equalization is described for magnetic recording. It is applicable to all (d,k) run-length limited codes. It is linear. Therefore, the amount of equalization does not vary with the write data pattern. It uses conventional two-level write current. A block diagram of the system is shown in Fig. 1. In the Fig. 1 system: T=desired Pulse Width; D=delay of T seconds; DN=delay of N x T seconds; MIN=time of shortest wavelength P=MIN . T DEL=required delay to align pulse with input Q=DEL . T The defining parameters are D, P and Q. An exemplary timing diagram is given in Fig. 2 for a (1,k) run-length code. If there is a head power dissipation problem, the write current may be sampled as shown in Fig. 3.